FILE SWITCHES

Dataplot utilizes a number of files. In some cases, these files are
previously created file names (e.g., the Dataplot help files, the file
containing the sign-on message). In other cases, these files are
dynamically named during a Dataplot session (e.g., the files
associated with READ, WRITE, or CALL commands).

In addition to the file name, there is also a Fortran unit number
associated with that file. Fortran unit numbers are typically between
1 and 99 (for Dataplot files, they typically are greater than or equal
to 10). Files also have a status value. A status value of OLD is
used for files that are expected to already exist (and are not
modified by the user during a Dataplot session). This would include
the help files, the file containing the sign-on message, and several
others. A status value of UNKNOWN is used for files that can be
modifed during a Dataplot session and that may not currently exist.
An example would be the file associated with the READ command.

Unit numbers are typically not changed and the file status is
determined dynamically. So these would typically only be used by the
PROBE command (i.e., not by SET). The SET command can be used to
change the name of the plot files (IPL1NA, IPL2NA). The SET command
would not typically be used to change the name of the other files
listed below.

These setting are typically of interest to the Dataplot developers for
debugging purposes. However, they can be used by any Dataplot user.